Pilot indicator for solenoid valves



NOV. 7, 1950 o v m 2,528,898

PILOT INDICATOR FOR SOLENOID VALVES Filed Feb. '3, 1946 3/ AWE/v T e:

DUI/61.9.5 K. MCI-I. VH/A/EJ Jaw W g Patented Nov. 7, 1950' 2,528,898 PILOT INDICATQR FOR SOLENOID VALVES Douglas K. Mcllvaine, Des Plaines, Ill., assigr'ior to Alco Valve Company, University a corporation of Missouri City, Mo.,

ApplicationFebruary 2, 1946, Serial No. 645,166

The present invention relates to'a pilot indicator for a solenoid valve.

It is an object of the invention to provide a solenoid having a main coil and a movable core.

with a secondary coil associated with the main coil, and adapted to be magnetically coupled thereto through the core when the core is moved by the energization of the main coil from one position to another. K It is an object of the invention to provide a pilot indicatorfor a solenoid having a main coil and a core, the indicator being such as a light that is illuminated when the core is on one position, and which cannot be illuminated when the solenoid is in its other position. More particularly, it is an object of the invention to provide a pilot light for a solenoid valve that will be illuminated only when the valve is open and which cannot be illuminated when the valve is closed. It is a particular object of this invention to provide such a pilot light that is operated by a voltage induced from the main solenoid winding, with a construction whereby such induced voltage cannot be developed when the valve is not open.

In the drawings: Fig. 1 is a vertical section through a valve of this type, with the pilot light attached to the cover;

Fig. 2 is a view of the solenoid with the pilot light shown as remote from the cover; and

Fig. 3 is a typical wiring diagram.

The valve illustrated in Fig. 1 is of the pilot operating type, although it will be obvious that other types of valves may be used. It will also be obvious that, while this invention finds paculiarvalue as an indicator for valves, it may be used for other purposes. The valve shown includes a valve housing In, having an inlet I I and an outlet l2, with an internal partition l3 there= between. A valve seat I 4 isfo'rme'd aspart of a port through the partition l3. v

The valve housing H] has a cvlindrical opening I 6 extending'downward from the top thereof and coaxial with the valve seat. This receives a main valve piston H which has a somewhat loose fit within the cylinder. This piston I6 is hollow, as at l8, and has a head l9 beveled so as to engage the valve seat I 4 and to flare outwardly therefrom. A pilot port 20 passes through the head i9.

A pilot Valve 2| is fitted within the opening l8 of the piston seat on the edge of the opening 20 through the head IQ of the main piston. A collar 22 is arranged on the pilot valve 2| and a stem 23 extends upwardly from this' c ollar 2'2. A closure plug or disc 24 is seated ac'rossthe top of the opening |8 on the valve piston Hand is secured. by a retainer ring 25. This plug 24 has ports 35 therethrough that are outward flm t is Qui limits of the collar 22'.

This pilot valve is adapted to 3 Claims. (Cl. 137-439) The stem '23 has a collar at its top. The upper part of this stem-is disposed in an axial opening 3| in a solenoid plunger or core 32. The lower end of the opening 3| is closed by a threaded plug 33, in the manner shown.

The plunger 32 is reciprocable within a tube 34 4 that has attached to its lower end a flanged collar 35 that may be held down by a union member 36 threaded onto the top of the valve housing In. 4

43 that supports a disc 44, and, above this, .an-,

other tube 45. The tube 45 constitutes the means about which the coils. of the present solenoid are wound.- Just above the bottom disc 44' is a coil disc 4?. Above it is wound a first coil '48, con sisting of only a few turns. Above the winding 48 is another coil disc 49, forming the lower end member for the main winding 50. The upper end of the coil 50 is held against an upper disc 5|. The tube 45 may be flared out somewhat at its upper end to confine the disc 5|. An inner sleeve 52 fits between the two tubes 34 and 45. It

' cooperates with the other sleeve 43 to hold the nections for the coils.

Above the casing 58 is a combination stud and nut 62 It is threadedover the extension 5'; on the plug 53, and thereby holds the cover 58 in p ace It will be seen that the cover engages the top of the sleeve 52, and thereby holds all of the coil'parts against the coil spring 42, so that they are yieldably supported in place. Upon removal ofthe cover 58, thevarious coil parts may be liftedoir of the tubular member 34. V

At its upper end, the stud 62 has a nut 64 that is suitably located to be engaged by the bottom of an upper cup-shaped cover 65. This last end cover is fitted over the top of the stud 62, which is threaded, and is held in position by a cap nut BB. w

The upper. cover 65 is provided with a side opening 61 therein. In the form of Fig. 1, the side opening is sized to receive a flanged and threaded s eeve 68 that is held in place by a nut 69 on the inner side of the cover. The sleeve 61, in turn, receivesa cylindrical light containing member it, having a lens 1| therein. The top of the cover 65, on its inner surface, receives' and s bmits an angina bracket- 12 that has a lamp 3 socket 73 mounted thereon with suitable electrical terminals 14 and I5. The lamp socket is adapted to receive a lamp 16.

In the form shown in Fig. 2, the opening 6'! need not be so large because it is adapted merely to provide an outlet for the two wires, whereby they may be directed to the lamp socket 83 which may be located in any desired point.

Typical connections are shown diagrammatically in Fig. 3. are connected by leads 86 and 81 to the ends of the short coil 48. The other coil 50 has leads 88 and 89 that are connected to a suitable source of power. The diagram of Fig. 3 shows the lamp 1B and the two leads 8B and 81 that are connected into the small winding 48. The two power lines 88 and B9 arejconnected into the coil 50. The operation of the device is as follows: The Valve is adapted to be open when some control, such as the switch S in Fig. 3, is closed.

This will energize the coil 50, which will thereby tend to raise the core 32. The valve may be any 7 Only a small movement of .the pilot valve is required. It. will be observed that the collar 22 on thepilot valve stem will not cut off the ports 26 in the disc 24 when the collar 22 reaches its upper position and abuts the disc.

When both valves are closed, the inlet pressure of the fluid in the inlet I I will be the same on the top side of the piston I! as it is in the inlet, owing to the fact that the gas may leak around the main piston l1. When the pilot valve is opened, this gas, at inlet pressure, escapesout the port through the bottom of the piston, whereupon inlet pressure acts on the annular and frusto-conical bottom surface of the piston l1 outside the limits of the valve seat I4, and lifts the piston so that the main valve is fully open. Subsequently, when the coil 50 is deenergized, the core 32 will drop and reclose the pilot'valve 2|, so that the pressures on the piston I! are again equalized and the piston will close against the valve seat [4. It isnot necessary to give a detailed description of the operation of the valve, because this mechanism is applicable to many varied kinds of valves or othersimilar devices.

When the coil 50 is energized, the adjacent turns 48 in the short winding will tend also to be energized by induction. When the core 32 is in 1 the lower position shown, the magnetic couplingis so weak that the current induced in the coil 48 is too small to cause the lamp 16 to be lighted. Consequently, this light will indicate, by its con.- dition, that the valve is closed. However, when the core 32 reaches its top position, wherein the valve is open, the core will establish adequate magnetic coupling between the main, and pilot coils to provide sufiicient induced voltage in the pilot coil to cause the lamp 16 to light, and thereby indicate that the valve is open. 1

It will be seen that the light acts as an indicator of the position of the core 32, and, consequently, will always indicate'the condition of the valve itself, rather than the condition of the main coil 50. Even if the core 32 is not raised when the coil 50 is energized, there will be no indication of an open condition of the valve by the lamp 16. a

The value of such a light as a sure indicator of The two terminals 14 and 15' the condition of the valve is obvious. Itis also noteworthy that it attains its advantage without requiring any opening of the'casing parts of the valve.

The invention may be given other applications wherein a secondary potential is required only when a solenoid core is in one of it positions.

What is claimed is: I

1. In a valve, a housing having a valve mounted therein for movement from first to second position, a first electromagnetic coil, a second electromagnetic coil separated from the first coil, a magnetic core connected with the valve and operab-ly disposed with respect to the first coil so that upon. energization of the coil .the core will .be

moved and the valve operated from first to'se'c- 0nd position, the second coilbeing positioned and the core being sized so. that the 'secondcoil, is magnetically coupled with the first coil by 'thef core only when the core has, been moved by the first coil away from its first position and toward its second position, and circuit connect-ions be tween the ends of the second coil, whereby a circuit may be energized only when the valve is in second position.

2. In a valve, a housing having-a valve mounted therein for movement from first to second posi-.

tion, a first electromagnetic coil, a second electromagnetic coil separated from the first coil,la. mag-- netic core connected with the valve and operably. disposed with respect to' the first coil so that upon' energization of thecoil the core will be movedv and the valve operated from first to second posi tion, the second coil being positioned and. the.v core being sizedso that the second coil is magnetically coupled with thefirst coil by the core. only when the core has been moved by the first coil away from its first position and toward its.

second position, and circuit connections between the ends of the second coil, whereby a circuit may be energized only when the valve isin second position, and an indicating-means in the circuit connections to indicate that the valve is in .sec-,

ond position.

3. In a mechanism of the kind described "fo1' having power, when energized, so to move the core, the core being of a size to magnetically couple the first and-second coils when the core is in second position but not when the core is in its first position, and a circuit connected with. the second coil to be energized when the second core is energized from the first by magnetic coupling through the core, and indicating means in 60" the circuit, operated when the core is moved by the first coil'to its second position;

DOUGLAS K. MCILVAINE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

